The present invention is directed toward methods and apparatuses for accessing microelectronic workpiece containers, such as FOUP containers.
Microelectronic devices, such as semiconductor devices and field emission displays, are typically fabricated on and/or in microelectronic workpieces using several different types of process machines (xe2x80x9ctoolsxe2x80x9d). A workpiece, for example, is often processed using tools for depositing, implanting, diffusing, doping, etching, polishing/planarizing, and patterning materials. A workpiece can typically undergo several processing steps within a single enclosed clean or xe2x80x9cminixe2x80x9d environment within a processing tool. For example, microelectronic workpieces can be plated with a conductive material, annealed, etched, and cleaned, using a plurality of processing chambers all housed within a single processing enclosure that defines a clean mini environment.
These processes can be performed on each workpiece individually in separate single-wafer processing chambers, and the workpieces can be moved from one processing chamber to the next, a technique referred to in the industry as single wafer processing. One initial problem encountered with single wafer processing was determining how to deliver individual workpieces to and from the enclosure while maintaining a clean environment within the enclosure. One approach to addressing this problem has been to load several workpieces in a portable container while the container is in a clean environment and then seal the container with a removable door. Accordingly, the interior of the container can define another clean mini environment. The door is then removed when the container is flush with a hatch of the processing enclosure to reduce the likelihood for introducing contaminants into the enclosure.
One conventional container having the foregoing design is a Front Opening Unified Pod (FOUP). In operation, the door of the container is positioned flush against the hatch of the processing enclosure to reduce or eliminate any non-clean gas volume between the door and the hatch, and the door and the hatch are then moved together into the enclosure, allowing access between the interior of the container and the interior of the processing enclosure. A robot then retrieves individual microelectronic workpieces from the container, delivers them to the appropriate processing stations, and returns them to the container after they have been processed. Once the container has been refilled with processed microelectronic workpieces, the removable door is put back in place and the container is moved away from the enclosure.
To improve the efficiency of the foregoing operation, it may be desirable to place a relatively large number of microelectronic workpieces in a single container. It may also be desirable to increase the size of the microelectronic workpieces. Accordingly, the container can become quite heavy when fully loaded with microelectronic workpieces, making the container difficult to handle.
One known approach to addressing the foregoing problem (shown schematically in FIGS. 1A-B) is to provide a processing enclosure 10 with a container intake section 12 that allows containers 13 to be loaded at an ergonomically suitable height. The container 13 is translated horizontally at the intake section 12 (as indicated by arrow xe2x80x9cTxe2x80x9d in FIG. 1A) to align a removable door 16 of the container with a door remover 18 of the enclosure 10. The door remover 18 can include a panel positioned in an aperture 15 of a movable frame 14. The door remover 18 engages the door 16 and moves it horizontally into the enclosure, as indicated by arrow xe2x80x9cU.xe2x80x9d Referring to FIG. 1B, the frame 14 and the container 13 move upwardly together on an elevator 20 (as indicated by arrow xe2x80x9cVxe2x80x9d) to align the open container 13 with a robot 19. The elevator 20 then indexes the container 13 upwardly and downwardly (as indicated by arrow xe2x80x9cWxe2x80x9d) to align each microelectronic workpiece in the container 13 with the robot 19. The robot 19 transfers each workpiece to one or more processing chambers 21 for processing, and then returns each workpiece to the container 13.
One drawback with the approach shown in FIGS. 1A-B is that moving the container 13 up and down to align the workpieces with the robot 19 can cause the workpieces to shift within the container 13. As the workpieces shift, they can be damaged, or the workpieces can become misaligned relative to the robot 19. The robot 19 may then be unable to retrieve the workpieces from the container 13.
Another problem associated with moving microelectronic workpieces into and out of a container has been determining which positions within the container are occupied by workpieces, and whether the workpieces in the occupied positions are properly seated. One approach to addressing this problem, disclosed in U.S. Pat. No. 6,188,323 to Rosenquist et al., is to mount a scanning device on a door opener that opens the door of the container. The door opener operates by engaging the door of the container and retracting the door horizontally into the enclosure and then downwardly away from the container. As the door opener moves downwardly with the door, the scanner moves past the workpieces in the open container and scans the workpieces with a beam of light. However, this arrangement may not provide for consistent scanning results and, in some cases, the scanner can mistakenly indicate workpieces in unoccupied positions, and/or mistakenly indicate no workpieces in occupied positions.
The present invention is directed toward methods and apparatuses for handling microelectronic workpieces initially positioned within a container. The container can be changeable from a first configuration with the microelectronic workpieces generally inaccessible within the container, to a second configuration with the microelectronic workpieces accessible for removal from the container. Several embodiments of the apparatus comprise a movable container support that positions the container next to an aperture of a workpiece processing tool, and then remains in a fixed, stationary position while the microelectronic workpieces are moved from the container into the tool and back again. An advantage of this feature is that microelectronic workpieces can be less likely to shift in the container because the container can remain in a fixed position while it is being accessed. Instead, a movable robot can index a sufficient amount to access each microelectronic workpiece within the container without moving the container itself.
Another feature of several embodiments of the apparatus is a scanner that scans the positions of the microelectronic workpieces (for example, with a focused beam of light) as the container is changed from the first configuration to the second configuration. The scanner can be mounted to a portion of the apparatus that does not move toward or away from the microelectronic workpieces. An advantage of this feature is that the scan be more accurate than some conventional scans because the focal point of the scanning beam has a consistent location relative to the microelectronic workpieces.
In one aspect of the invention, the apparatus can include a container access device positionable proximate to an aperture of an enclosure that at least partially encloses a region for handling the microelectronic workpiece. The container access device can be movable to change the configuration of the container from the first configuration to the second configuration. The apparatus can further include a container support movably positioned proximate to the aperture, with an actuator coupled to the container support to move the container support between a first position at a first height and a second position at a second height different than the first height. The container support can be configured to support the container in a fixed, stationary position relative to the aperture when the container is in the second configuration and positioned to have the microelectronic workpiece removed. For example, the container support can include an elongated pin received in a corresponding opening of the enclosure to at least restrict motion of the container support.
In a further aspect of the invention, the container can have a plurality of workpiece support members, each configured to support a microelectronic workpiece. The workpiece support members can include a first workpiece support member and a second workpiece support member with the second workpiece support member positioned further than any of the other workpiece support members from the first workpiece support member. The apparatus can further include a workpiece transfer device having an engaging portion configured to releasably engage the microelectronic workpieces. The workpiece transfer device can be movable relative to the housing to move the microelectronic workpieces, and can have a range of travel that extends from a first position aligned with the first workpiece support member of the container to a second position aligned with the second workpiece support member of the container.
In yet another aspect of the invention, the microelectronic workpieces can be spaced apart along a first axis, and the container access device can have a movable portion movable relative to the aperture along a second axis at least approximately parallel to the first axis to change the configuration of the container from the first configuration to the second configuration. The apparatus can further include a workpiece detector operatively coupled to the movable portion of the container access device to move with the movable portion along a third axis at least approximately parallel to the second axis, but not toward or away from the second axis. The workpiece detector can be configured to detect a presence, absence, and/or position of a microelectronic workpiece in the container.
The invention is also directed toward a method for handling microelectronic workpieces. In one embodiment, the method can include positioning a container on a container support external to an enclosure at least partially surrounding a region for handling a microelectronic workpiece. The container can have a plurality of microelectronic workpieces and the method can further include elevating the container and the container support from a first position to a second position above the first position, and changing a configuration of the container from a first configuration with the microelectronic workpieces generally inaccessible within the container to a second configuration with microelectronic workpieces accessible for removal from the container. The method can further include securing the container to be fixed relative to the enclosure when the container is in the second position (for example, by engaging a pin of the container support with an aperture of the enclosure), and moving the plurality of microelectronic workpieces from the container through an aperture into the enclosure while the container remains in the fixed position relative to the enclosure.
In one aspect of this method, the container can include an opening with a cover removably positioned at least proximate to the opening and changing the configuration of the container can include moving the cover from an attached position to a detached position. In another aspect of this method, the container can include a plurality of microelectronic workpieces spaced apart along an axis. The microelectronic workpieces can include a first microelectronic workpiece and a second microelectronic workpiece with the second microelectronic workpiece positioned further than any of the microelectronic workpieces from the first microelectronic workpiece. The method can include aligning a workpiece transfer device with the first microelectronic workpiece and engaging the workpiece transfer device with the first microelectronic workpiece to remove the first microelectronic workpiece. The method can further include moving the workpiece transfer device to align the workpiece transfer device with the second microelectronic workpiece, and removing the second microelectronic workpiece from the container.
In another aspect of the invention, the method can include positioning a container proximate to an aperture at least partially enclosing a region for handling a microelectronic workpiece, with the container having a plurality of microelectronic workpieces spaced apart along a first axis. The method can further include changing a configuration of the container from a first configuration with the microelectronic workpieces generally inaccessible within the container to a second configuration with the microelectronic workpieces accessible for removal from the container by engaging a container access device with the container and moving a movable portion of the container access device along a second axis at least approximately parallel to the first axis. The method can still further include detecting a presence, absence, and/or position of microelectronic workpieces in the container by moving a workpiece detector together with a movable portion of the container access device as the movable portion moves along the second axis and without moving the workpiece detector toward or away from the first axis.